Surgical pads

ABSTRACT

Surgical pads for relieving the pain of corns, callouses, bunions, abrasions, etc., which pads are made of thermoplastic chemical foam and each having an affliction-receiving cavity pressed into the body of the pad from the underface of the pad.

United States Patent [191 Johnston 1 1 SURGICAL PADS [75] Inventor: JohnJohnston, Michigan City, Ind.

[73] Assignee: Scholl, Inc., Chicago, Ill.

[22] Filed: Sept. 22, 1971 21 Appl. No.2 182,746

Related US. Application Data [62] Division of Ser. No. 865,604, Oct. 3,1969,

[ June 26, 1973 3,062,208 11/1962 8611011 128/153 2,081,716 5/1937$611011 128/153 2,098,312 11/1937 $611011 128/153 3,086,523 4/1963 LOWih128/153 2,914,109 11/1959 1'18 61231.. 264/D1G. 46 3,370,117 2/1968B1116 264/321 3,378,432 4/1968 Spencer 264/321 X 3,544,675 12/1970 BelleIsle 264/321 FOREIGN PATENTS OR APPLICATIONS 835,303 5/1960 GreatBritain 128/153 Primary Examiner-Richard A. Gaudet Assistant ExaminerJ.Yasko Attorney- Carlton Hill, J. Arthur Gross, M. R. Chambers et al.

[57] ABSTRACT Surgical pads for relieving the pain of corns, callouses,bunions, abrasions, etc., which pads are made of thermoplastic chemicalfoam and each having an afflictionreceiving cavity pressed into the bodyof the pad from the underface of the pad.

4 Claims, 8 Drawing Figures SURGICAL PADS CROSS-REFERENCE TO RELATEDAPPLICATION The instant application is a division of my copendingapplication filed Oct. 13, I969, Ser. No. 865,604, now abandoned underthe title Surgical Pads and Method of Making the Same, and now entitledMethod of Making Surgical Pads."

SUMMARY OF THE INVENTION In the past, in the manufacture of surgicalpads have an opening or cavity therein to receive an affliction ormedicament, or both, and eliminate pressure upon the affliction, it wascommon practice to die-cut a'hole in the body of the pad when the padwas cut from a sheet of stock of indefinite size. Difficulty wasexperienced in getting rid of the small piece of waste where the holewas cut. Where a cover was desired over the afflictionreceiving cavityit was necessary to laminate an extra piece of material to the pad bodyon the face thereof opposite the one carrying'the adhesive, and in manycases such a cover is found desirable, especially where the afflictionmay be open or a certain type of medicament is indicated forthataffliction. Manufacture of the covered pads was consequentlyobjectionably expensive.

While this application claims the invention as a product or article ofmanufacture, in order to better'describe the specifics of the invention,reference will be herein made to the method of making the pads, whichmethod is claimed in my aforesaid parent application.

The present invention overcomes the difficulties mentioned above asoccurring in the past, and materially reduces the cost ofmaking padswith a covered de pression or cavity for receiving an affliction. Thepads of the instant invention are each made from a single unitary pieceof material. This is accomplished by the use of hot die means andcutting the pad from a stock sheet of synthetic resin or chemical foammaterial which can be purchased in sheet form with a smooth skin-likesurface necessitating no cover thereover. contemporaneously with thecutting of the pad, a hot probe contacts the adhesived face of the padbeing formed and presses a depression or cavity in the body of the padby collapsing the cells of the foam and establishing a denser materialover the probe. As a result, there is an affliction-receiving cavitythat has a cover thereover. The pad may be formed in one operation froma stock strip of adhesive-bearing foam and no material is removed fromthe pad body proper, eliminating the need of disposing of small bits ofwaste where holes were previously cut and eliminating the operation oflaminating a cover over one surface of the pad body having a holetherethrough. The result is a pad of high and durable quality, having anexcellent cushioning effect and which may be manufactured moreeconomically than'heretofore.

Other objects, features and advantages of the present invention will bereadily apparent from the following detailed description of severalembodiments thereof when taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary verticalsectional view of die means used and illustrating an initial step in theoperation of making the pad;

FIG. 2 is a view similar in character to FIG. 1 but showing the pad inits formed state;

FIG. 3 is a fragmentary plan view of pads shaped and cut but prior tothe removal of waste stock;

FIG. 4 is an enlarged fragmentary vertical sectional view takensubstantially as indicated by the line IV-IV of FIG. 3;

FIG. 5 is a fragmentary vertical sectional view of a pad of slightlydifferent construction;

FIG. 6 is a fragmentary vertical sectional view through a pad havingflocking on the top thereof;

FIG. 7 is a fragmentary view illustrating that the probe may be usedthrough a sheet carrying a release facing; and

FIG. 8 is a bottom plan view of a pad of different shape to illustratethat the shapes of the pads may be varied in accord with their specificpurposes.

DESCRIPTION. OF THE PREFERRED EMBODIMENTS The pads of the instantinvention may be of any desired size and shape depending uponthe'particular use for which an individual pad is intended. The pads arepreferably cut from the stock sheet by die means usable in a known formof electronic heat-sealing press. Such die'means are best seen in FIGS.1 and 2. There is an upper die, generally indicated by numeral 1 and alower die generally indicated by numeral 2. Both'dies are electricallyconductive and may be connected by conductors 3 and 4, respectively, toa source 5 of ultra high or radio frequency current, diagrammaticallyshown.

The upper die comprises a conductive backing 6 from which a conductiveskirt 7 depends, the skirt being shaped in accordance with the boundingoutline of a pad to be formed. The skirt is beveled as at 8, on theinner side thereof, terminating in a knife edge 9. Inside the skirt in alocation where an afflic'tion-receiving cavity may be desired, a plug 10of insulating material depends from the back member 6 to act as a backupfor a probe to be later described.

The lower die 2 may be in the form of a flat plate having an aperture 11therein through which a probe 12 is reciprocated by any suitable means.This probe, inside thereof, carries one or more electrical heating units13 of aknown variety. The material from which the pads are made ispreferably a high density plastic foam, such a plasticized polyvinylchloride,'polyurethane, polyurethane impregnated with polyvinylchloride, of which the density is usually 10 to 15 pounds per cubicfoot, depending on the desired cushioning effect. Other thermoplasticfoams that may be utilized include polyethylene, polypropylene, orSurlyn-A Ionomer, among others. The foam thickness can vary, dependentupon the end usage, and usually foam the thickness of onesixteenth inchto one-eighth inch is satisfactory for most purposes. Such foam can beobtained in sheet form having an integral natural smooth finished skinon one side thereof, whereby nothing else is needed as a cover for thefoam, unless some specific type of cover or appearance is desired.Either open celled or closed celled foam may be utilized, since theresult will be the same in either instance.

The forming of a pad is a simple and rapid operation. A stock sheet orstrip 14 of indefinite size is placed over the lower die 2, the strippreferably carrying a pressure sensitive adhesive spread on its underface. The upper die 1 is then lowered under pressure from the positionof FIG. 1 to the position of FIG. 2 thus shaping and substantiallysevering a pad 15 from the stock strip. The inner bevel on the skirt 7of the upper die shapesthe bounding edge of the resultant pad and whenthe dies are charged with radio or high frequency current, a nicerounded shape as indicated at 16 in FIG. 4 is permanently formed in thepad as a result of the heatsealing operation. Contemporaneously with thelowering of the upper die 1, the probe 12 is forcefully elevated fromthe position seen in FIG. 1 to that of FIG. 2 the block of insulatingmaterial carried by the upper die acting as a backup for the probe sothere is no deformation in the upper face of the pad, and the squeezingaction between the probe and the backup collapses the cells in the foamabove the probe and provides an affliction-receiving cavity 17. Theprobe is heated to the softening temperature of the particular foambeing utilized, in the general range'of 20 to 40 below the melting pointof the foam. The heat and pres.- sure of the probe destroys the cells inthe foam in the region 18 above the probe, adding to the density of thefoam in this region and permanently establishing the cavity 17 coveredby the denser material 18. Thus, the need for removal of any wastematerial resulting from the cutting of an aperture through the body ofthe pad is eliminated.

Whether or not the adhesive contacted by the probe is destroyed isselective. For example, the probewill not destroy an acrylic, or otherhigh temperature resisting adhesive which remains stable to a highertemperature than that of the probe. Medicament may then be placed in thecavity and held there by way of the adhesive surface on the underside ofthe covering portion 18. On theiother hand, if it is intended that thepad be placed over an open affliction such as a cut or a wound,

an adhesive may be utilized that will be destroyed by the heat of theprobe and then there will be no adhesive contacting the particularaffliction.

The pad is accordingly extremely economical to manufacture, the upperdie being forced down, the probe forcedup, the electrode dies arecharged with high frequency current, and the pad is complete within avery few secondsfllhe waste stock is easily stripped from the completedpad by virtue of the action of the knife edge 9 on the upper die and thecharge of current passing therethrough.

In the example of FIG. 4, a pad is formed solely from the foam itself,the foam being of the type having a smooth external skin,diagrammatically indicated at 19 which necessitates no other covering,that skin being sufficiently smooth to permit the rapid donning ofarticles of apparel without any snagging of the pad.

Should it be desired for decorative purposes or any other reason,acolored thin sheet or film, such as a vinyl film 20, may be placed overthe foam as seen in FIG. 5. The foam may be obtained with the sheet 20already laminated thereto, or such a sheet or film may be laid over thestock strip 14 and when the pad is formed the cover 20 will be heatsealed to the foam in the marginal region 21.

Heretofore, pads of this general type have been most frequently madewith a top layer of napped or pile fabric, such as moleskin. The sameeffect can be obtained, if desired, in the instant pads by merelyutilizing a foam having a flocking on its upper face, as shown at 22 inFIG. 6. The flocking may be cotton, rayon, nylon, or equivalent fibers,and the resultant pile size can be of selective heights, usually fromone to three millimeters being satisfactory. The formation of a pad inthe manner above described does not change the contour of the pad, aflocked pad having the same smooth curvature around the bounding edge.

It is usually desirable to cover the entire adhesive spread on the stockstrip with a sheet of material having a release facing as customarilyused to protect an adhesive face until the pad is put to use. In FIG. 7,I have made an exaggerated showing of a'pad with the adhesive spreadindicated at 23, and a protective sheet 24 disposed over that adhesiveface, the protective sheet being of paper having a release coatingthereon or any other suitable material. As long as the protective sheet24 is capable of withstanding the temperature of the probe 12, the probemay be applied directly to the protective sheet and anafflictionreceiving-cavity 25 will be formed in the resultant pad in thesame manner as above described.

In FIG. 8 I have shown the underface ofa round pad 26 having anaffliction-receiving opening 27 therein made in the same manner as pad15 above described, this showing being merely to illustrate possiblevariations in pad shape. 7

Although various minor modifications might be suggested by those versedin the art, it should be understood that I wish to embody within thescope of the pa-' tent granted hereon all such modifications asreasonably and properly come within the scope of my contribution to theart.

I claim as my invention:

1. In a cushion type surgical pad for relieving an affliction frompressure,

a unitary body of thermoplastic cellular foam,

said body having an affliction receiving cavity opening from theunderface thereof,

a compressed portion of said body in which the cells of the foam aredestroyed covering and maintaining the permanence of said cavity, and

means to attach the pad directly to the body of a user.

2. The surgical pad of claim 1, wherein said body part is one-piece andhas a smooth integral surface forming the upper face of the pad.

3. The surgical pad of claim 1, wherein said means to attach the padcomprise a pressure sensitive adhesive spread on the underface of saidbody part and lining said cavity.

4. The surgical pad of claim 3, including a protective release sheetcovering the, exposed face of said adhesive spread and extends into saidcavity along with the adhesive in said cavity.

2. The surgical pad of claim 1, wherein said body part is one-piece andhas a smooth integral surface forming the upper face of the pad.
 3. Thesurgical pad of claim 1, wherein said means to attach the pad comprise apressure sensitive adhesive spread on the underface of said body partand lining said cavity.
 4. The surgical pad of claim 3, including aprotective release sheet covering the exposed face of said adhesivespread and extends into said cavity along with the adhesive in saidcavity.